The present invention concerns a breast prosthesis to be worn in a brassiere or the like, with a prosthesis body which has a front side having the shape of a natural breast, a back side provided with a recess and an edge of the prosthesis which follows a closed line, along which the front side and the back side of the prosthesis body each end, and the prosthesis body has a soft elastic silicone rubber compound enclosed without any voids in a bag consisting of two elastically expandable plastic films bonded tightly together along the edge of the prosthesis.
Such a breast prosthesis was presented and described in European Patent No. 657,148 A1, for example. With this breast prosthesis, one or more reinforcing ribs run vertically in the upright position of the prosthesis wearer and parallel to the longitudinal axis of the wearer's body; the function of these reinforcing ribs is to prevent the prosthesis body from sagging under the influence of gravity when the prosthesis wearer is in an upright position. In other words, the reinforcing ribs should guarantee the dimensional stability of the prosthesis when the wearer is in an upright position. However, the reinforcing ribs of the known breast prosthesis also have the effect of maintaining the shape of the prosthesis body even when the prosthesis wearer is lying down, because they prevent the prosthesis body from stretching horizontally under the influence of gravity when the prosthesis wearer is lying down. Many prosthesis wearers perceive it as unnatural when the prosthesis has the same shape when the wearer is lying down as when standing. To put it more explicitly, these prosthesis wearers have complained that this prosthesis does not flatten out somewhat when lying down in comparison with standing up in accordance with the natural conditions. Especially if very soft breast tissue is to be replaced with the prosthesis, as is often the case with older patients, it is perceived as a disadvantage that the prosthesis projects away from the wearer's body with an unnatural stiffness when lying down.